Are you ready to find baby galaxies?

When you participate in Galaxy Nurseries, you’ll have the opportunity to view real data as you search for emission associated with young galaxies in the early universe.

Courtesy of Zooniverse

Zooniverse is a revolutionary citizen science initiative led by Chicago’s Adler Planetarium and the University of Oxford. The platform hosts a wide range of projects that allow anyone, of any age and background, to engage in current ongoing scientific research in a fun, understandable, and simple way. On May 31, Zooniverse launched its 100th project on its 10th anniversary: Galaxy Nurseries, a hunt for young galaxies in the distant universe, which were forming stars about 5 to 7 billion years ago.

And the Galaxy Nurseries team has an ambitious goal — complete Zooniverse’s 100th project in 100 hours. The clock is ticking, but there’s still plenty of time left; if you’re interested in exploring the early universe and lending your eye to identify these amazing objects, consider taking a little time this weekend to make some classifications of your own.

Searching for young galaxies

Galaxy Nurseries takes advantage of a unique dataset provided by the Hubble Space Telescope (HST) as part of the WFC3 IR Spectroscopic Parallel (WISP) survey. When searching for young, star-forming galaxies in the early universe, simply taking an image is not enough. To get more information, these images not only provide a classical “picture” of everything in a given field of view, but also a spectrum for every single object Hubble can spot. A spectrum is essentially the result of passing light from an object, such as a star or galaxy, through a prism, which breaks the light apart by wavelength. As the light is spread out, it gives clues about the object’s nature. In particular, star-forming galaxies will show features called emission lines.

Emission lines indicate material such as gas that is glowing brightly, and only hot stars are capable of producing the radiation needed to excite nearby gas enough to produce certain emission lines. Because these huge, extremely hot stars don’t last very long (in the cosmic scheme of things), their existence is indicative of recent star formation. And these young star-forming galaxies are exactly what the researchers behind the Galaxy Nurseries project are after.

Why? There are two main reasons behind the development of the 100th Zooniverse project. First, there’s the underlying science. Claudia Scarlata, a physics and astronomy associate professor at the University of Minnesota and principal investigator of the Galaxy Nurseries Zooniverse project, explained to Astronomy that these galaxies are “extreme objects that are not specifically targeted for spectroscopy” in most surveys. Traditionally, obtaining spectra is harder than simply taking an image — it often requires more light, and can thus be challenging for such small, faraway objects.

Astronomers have sometimes gotten around this problem by classifying galaxies based on their colors in images. But “these galaxies have booming [emission] lines,” Scarlata said, “and their colors can be changed. They are often misclassified in broadband surveys,” that simply look at the color of the light coming from objects in an image.

But through the WISP survey, “we have a spectrum of every object in the Hubble field of view,” Scarlata says. Armed with this information, these objects now have spectra that can be analyzed, helping researchers such as Scarlata and her colleagues study star formation in the distant universe. There are several questions the team is looking to answer. How are these galaxies forming stars over time? What is their environment like? Are they isolated or found in groups? Are they dusty, or not? (Current research, Scarlata says, indicates the latter.) What type of metals (elements heavier than hydrogen and helium) do these galaxies have? “Averaging a large number of objects can give you the numbers you need,” Scarlata says, to start characterizing these young galaxies, which have been previously studied only in very small samples.

But, Scarlata says, there will be contaminants, such as active galactic nuclei, Milky Way stars, and even gravitational lenses. The goal of Galaxy Nurseries is to screen out these contaminants by showing volunteers what to look for, then letting them loose on the most promising data to determine whether the detection is real or spurious.

But even these contaminants hold scientific value. While the initial goal of Galaxy Nurseries is to identify these young galaxies, Scarlata says that volunteers will undoubtedly find new and strange objects during the search. “We’re also looking for the unexpected,” she says, “and we will follow up on everything, even if it’s not the galaxies we’re looking for.”

Improving how science is done

The second reason Galaxy Nurseries is so important is the potential it holds to make searching for galaxies and other scientific objectives and more accurate in the future. Specifically, there are two upcoming missions that will use similar techniques to find objects of interest: the NASA/ESA Euclid mission and NASA’s WFIRST telescope. The work that volunteers put into Galaxy Nurseries, Scarlata says, “will help us determine what works, what doesn’t, and where the volunteers are needed most.”

For example, Euclid will gather similar data, but “WISP has covered something like half a degree of the sky. Euclid will look at 15,000 square degrees — that’s an area 30,000 times larger than WISP,” she says. Thus, the information gained from Galaxy Nurseries and the other projects hosted on Zooniverse will pave the way for not only better machine learning to increase real detections in these larger datasets, but also improve projects’ ability to utilize citizen science volunteers even more efficiently and beneficially in the future.

“That’s the magic of Zooniverse, says Michelle Larson, the president and CEO of the Adler Planetarium. “Zooniverse continues to push itself. It’s about scientific progress.” As volunteers put their time into the various projects offered, it allows researchers and software developers alike to improve upon the aspects of science that machines can handle, as well as continually zooming in on the tasks that only humans can perform.

Coming full circle

Galaxy Nurseries is also a fitting 100th project for Zooniverse. The origin of the Zooniverse platform itself lies in the Galaxy Zoo project, launched in 2007. Thus, a 100th project brings the concept full circle; “We’re going back to the origin. It started with galaxies, and now it’s coming back to galaxies,” Scarlata says.

Galaxy Zoo was born from the need to parse through a huge volume of data in a reasonable way, which would have been unfeasible for one person or even several working together. And “the response was overwhelming,” Chris Lintott, an astronomer currently at the University of Oxford who is the co-founder of both Galaxy Zoo and Zooniverse told Astronomy. “Galaxy Zoo was not supposed to still be running 10 years later,” Lintott says. But it is — and Zooniverse projects have been responsible for some amazing discoveries, including Hanny's Voorwerp and an exoplanetary system with four super Earths.

And, if you’ve read about the third successful detection of gravitational waves by the Laser Interferometer Gravitational-Wave Observatory (LIGO) that’s currently topping science news, you might also be interested in checking out another Zooniverse project: Gravity Spy, which allows citizen scientists to help gravitational wave researchers filter out “glitches” in the data so that real signals can be found more easily.

Zooniverse projects have produced over 100 peer-reviewed science publications, and there are currently more than 1.5 million registered users from around the world participating in projects that largely focus on astronomy, but also include biology, climate science, history, language, literature, medicine, and animal behavior. Whether you want to find exoplanets, count wildebeest in the Serengeti, or further research on cellular structure, there’s a Zooniverse project for you.

“Zooniverse is inclusive,” stresses Lintott. “It’s about discoveries we can make together.”